It's mainly for checking pubertal development in that area, if there's a problem with retarded or precocious puberty - it's a gauge of development that's more central and fundamental than things like body hair.

An orchidometer is the best way to measure testicle size, as it measures volume of them. But, since they are oval shaped, you can get an approximate length of them with a ruler. Most average adult testicles are about 2.0 inches long each, and about an inch across. Large would be 2.5 to 3.0 inches long, IMO.

You know you have big balls when they get in the way while walking, or you sit on them sometimes hehe, some women(and men) like partners with big balls! Can really be a turn on. ::pours angel some coffee::: Starbucks!